A recently discovered exoplanet called LP 890-9c, situated 98 light-years away from Earth, holds the potential to offer insights into the transformation of habitable planets like Earth into inhospitable worlds like Venus.
This exoplanet orbits a small and cool red dwarf star, and its position near the inner edge of the star’s habitable zone makes it an intriguing subject for scientific study.
Known as LP 890-9c or SPECULOOS-2c, this exoplanet was detected in September 2022. According to Space.com, it has a diameter approximately 40% larger than that of Earth. Similar to our planet’s orbit around the Sun, this small and cool exoplanet completes its orbit around its star every 8.5 Earth days, at a distance of 1.7 million miles or 2.8 million kilometers.
LP 890-9c lies in close proximity to the inner edge of the conservative habitable zone (HZ). However, despite its proximity to the star, the exoplanet maintains a relatively cool temperature. In comparison, Earth is situated 152.07 million kilometers away from the Sun. This indicates that even in close proximity to a star, a planet’s temperatures can remain mild.
A research team led by Lisa Kaltenegger from the Carl Sagan Institute at Cornell University has utilized LP 890-9c as a model to study its potential climatic and atmospheric states. The team explored how the James Webb Space Telescope (JWST) could differentiate between these states.
The exoplanet’s location in its planetary system is similar to Venus’ position in our solar system, with both planets situated at the inner edge of the habitable zone. However, not all planets in similar positions will necessarily follow the same path as Venus, which became inhospitable due to a runaway greenhouse effect.
If LP 890-9c possesses a strong magnetic field, unlike Venus, it may be able to retain water vapor in its atmosphere and maintain habitability. By studying LP 890-9c, researchers hope to gain insights into how long a rocky planet can remain habitable when it becomes hotter.
The research team developed various models of LP 890-9c, considering factors such as mass, radius, chemical composition, surface temperature, atmospheric pressure, and cloud cover. Five different models were created, ranging from a hotter version of an Earth-like planet to models resembling Venus.
By observing LP 890-9c during its transits across its host star, the JWST could determine the planet’s atmospheric composition. This observation could help determine whether the exoplanet possesses a steamy, water-rich atmosphere similar to Earth or exhibits similarities to Venus.
Studying LP 890-9c and its evolution can provide valuable information about the inner edge of habitable zones around stars and the longevity of rocky planets in such regions. Even if LP 890-9c proves unsuitable for life, analyzing its fate can offer insights into Earth’s future as our own sun continues to evolve and grow brighter.
The research findings were published in two papers in the Monthly Notices of the Royal Astronomical Society.
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